trouble caliberating my meter for my camera.

Discussion in 'Exposure Discussion' started by Dikaiosune01, Mar 21, 2011.

  1. Dikaiosune01

    Dikaiosune01 Member

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    I use a digital slr to meter for a 4x5 camera. im having some trouble caliberating my meter. I dont know what is the cause. Is my assessments of my negatives wrong? Or if i calculated filter factors incorrectly. Or are my prints off? With so many variables it is hard to pin down the problem. Knowing myself, it is probably everything.
     
  2. Mainecoonmaniac

    Mainecoonmaniac Subscriber

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    Are you shooting up close with your 4x5? I'm thinking of bellows factor. Also is the scene identical between cameras? You also have to see how your dslr meter is weighted in your view finder. Your meter on your dslr can be biased for certain scenes and subjects.
     
  3. naeroscatu

    naeroscatu Subscriber

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    You are not very specific in explaining your problem. Why do you need to calibrate your DSRL meter?
    There are many variables indeed. Before starting using a set of equipment (camera + light meter + film + lens + enlarger + paper) you need to run some tests. That is if you want to eliminate guess work and get controlled results. You should check numerous articles and books about film testing.
     
  4. Nicholas Lindan

    Nicholas Lindan Advertiser Advertiser

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    You should get a light meter - a small Gossen shouldn't cost more than $25 on ebay.

    A digital camera sets the aperture and shutter to satisfy its image sensor - not film.
     
  5. Shaggysk8

    Shaggysk8 Member

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    Why do you say they are not right? What makes you think they are wrong?
     
  6. benjiboy

    benjiboy Subscriber

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    I understand that from a recent article I read in Professional Photographer magazine testing hand held light meters,that 100 I.S.O on a digital camera sensor doesn't necessarily give the same speed as 100 ISO on film.
     
  7. Dikaiosune01

    Dikaiosune01 Member

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    It is more likely i am wrong somewhere in the process. Ill try to be a little more specific about my current process.

    No bellows factors. Everything is far enough away.

    Meter: canon 500d + 300mm (75-300 zoom)
    monocrome setting, spot meter.
    Iso 400 overexposes. Iso 200 better, looking to fine tune it further. For the purposes of this exercise, my meter will be set to iso 200.

    Camera 4x5 (shen hao, but i dont think that is too important)
    film: hp5 400
    lens: 180mm shenider on copal shutter.

    i also use filters. I use the filter on the meter, no further compensation takes place. I meter. Plan my zones based on iso 200 for 400 speed film. Preview on the camera back. Checking my tones.

    checking the negatives, the shadows seems good. Then again im not the most experienced to judge.

    Final result prints. They seem quite off. I lose a lot of shadow on the prints. The prints that used the iso 200 setting on the meter are better than the 400. but there seems to be room for improvement. I want to shoot closer to the mark.

    I apreciate the help fellas.
    (typed on a phone. I apologize for typos)
     
    Last edited by a moderator: Mar 22, 2011
  8. Mainecoonmaniac

    Mainecoonmaniac Subscriber

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    You also can't compare digital sensors with film. I think the response of digital light sensors are linear while film has a response curve. Could be an apples to oranges comparison. Please tell me of I'm wrong.
     
  9. Vaughn

    Vaughn Subscriber

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    What reached out and grabbed me on your last post was that the shadows seem to be fine on the negatives, but get lost on the prints. This tells me it is more of a matter of how the meter is used and your negative developing and printing skills...and has little or nothing to do calibrating the DSLR's meter.

    If getting a good print was just a matter of proper exposure, a little bit of bracketing and note-taking could have that nailed down for any particular lighting situation in an afternoon. Unfortunately, how the film is developed, and how one prints is of equal importance. One can have properly exposed film (good shadow detail), but depending on the light (high, medium or low contrast scene), how you develop that film will determine how easy it will be to transfer the light of the scene onto the print in the way that you want.

    And of course, your printing skills will determine how easy it will be to take a well exposed and developed negative to translate into a print.

    But at this point I do not know how you are getting these prints -- are you printing them? And if you are, what contrast controls are you using in your printing process?
     
  10. Shaggysk8

    Shaggysk8 Member

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    Ok you really need to do some proper test like in way beyond monochrome
    http://www.waybeyondmonochrome.com/WBM2/Library.html

    But if you don't wanna do that my advice would be use Iso 200 develop 15% less than stated by ilford with chosen developer. Then get a even textured surface evenly lit and point your spot meter at it and expose at zone 2 and then a zone 8 these zones should be lightest and darkest with texture.

    But from my own experience you really need to do proper test also paper tests.

    I would also for a quick paper test, develop a blank neg (this will give you film base + fog) and place it in your enlarger and print a test strip at 3 secs apart then develop as normal allow to dry and look for the time that is maximum black, then when your other tests are done print at this time and this will give you an idea what a zone two will look like and an 8, if the two is too dark try a different iso if the 8 is too light reduce dev time by 15% if its too dark increase dev time.

    Then once that it done, go out take a pic without filter, bellows extension but with a good range of tones and try and print it. If all works out ok then you can go at and any mistakes you can at least narrow down a bit more.

    Paul
     
  11. markbarendt

    markbarendt Subscriber

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    Given that the negatives have detail where you want it, I'm going to say it's a problem in the printing.

    Negatives are very forgiving and normally carry a lot more of the scene brightness range than what can easily be printed.

    You may need to do some burning and dodging or ...
     
  12. jerry lebens

    jerry lebens Member

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    I can't see any reason why using a DSLR meter shouldn't work, even if the readings are 'wrong' - as long as they're consistently wrong, everything should work out fine. It's only if you later use a different meter that problems may arise.

    I don't wish to appear rude but I'd suggest that, from the way you presented your question, you've not quite understood how the zone system works : When you say you are 'planning your results on iso 200', does that mean you've done film speed tests to confirm that the 'actual iso' is 200? Or have you decided on it arbitrarily? If so, then you aren't using a zone system but guessing and that isn't really how the system operates.

    I'd look at Ralph Lambrecht's site or here http://www.silverprint.co.uk/pdf/Goldfinger.pdf (Page 11 onwards, It's very poorly reproduced but it's a simple method that works).

    Regards
    Jerry
     
  13. jnanian

    jnanian Advertiser Advertiser

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    it might take a few sheets of film
    but why don't you bracket your exposures to find
    out what your "personal iso" is when you use your d-cam
    as your light meter ?
    don't just make the negatives, but make prints of each exposure.

    if / when you get a new meter, you will probably have to do something
    similar just to fine tune your exposure+printing.

    good luck !
    john
     
  14. outwest

    outwest Subscriber

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    There is also the very good chance that your digital camera has accurate shutter speeds whereas your Copal shutter is running a bit slow (or maybe a lot slow in the case of the higher shutter speeds). This would cause your overexposure and it could vary at different shutter speeds.
     
  15. Shaggysk8

    Shaggysk8 Member

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    Yeah shutter speeds just to give you an idea, i tested mine and this is what i got

    5.6/210
    1 = 1 sec
    1/2 = 1/2
    1/4*= 1/5
    1/8*= 1/7
    1/15*= 1/14
    1/30*= 1/30
    1/60*= 1/60
    1/125*= 1/100
    1/250*= 1/150
    1/400*= 1/175

    So you can see it's very important to know you equipment.

    Paul
     
  16. Poisson Du Jour

    Poisson Du Jour Member

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    What stepping is the DSLR set to for metering? That 75-300mm zoom strikes me as oddly-fitted to the task for metering: the camera compensates for zoom extension. If the camera has multispot and average capability, use that rather than a single spot reading. What strikes me is how cumbersome this exercise appears. Invest in a hand-held meter.

    As each exposure comes out through the trial, get prints done from it as "reference cards" to what you are doing.